Powered personal lifting devices assist personnel in scaling vertical surfaces. Motorized winches are used to raise or lower personnel on platforms or harnesses attached to ropes. A winch must be anchored to a solid platform above the load or use pulleys coupled to the platform to hoist the load. Further, a winch winds the rope or cable on a spool which limits the length and weight of rope that can be used. Hoists, usually with compound pulleys or reducing gears are used to raise or lower individuals or platforms and must be suspended from a secure support point such as a tripod, beam or bridge crane. Typically a winch or hoist requires at least a second person to operate or control the device in order for a first person to safely ascend a rope.
There are however many examples of where it would be desirable to have access to a portable winch, preferable for a portable winch that can be operated by the person ascending or descending the rope. Such scenarios include for example mountain climbing, caving, tree trimming, rescue operations and military operations. Industrial uses of a climbing device may include scaling tall structures, towers, poles, mine shafts or bridge works for servicing, cleaning, window washing, painting, etc.
An example of such a portable winch is disclosed in U.S. Pat. No. 6,412,602. In U.S. Pat. No. 6,412,602 there is provided a promising approach to a portable climber operated winch, denoted as a climbing device, comprising a rotatable rope pulley connected to a motor, such as for example an internal combustion motor or an electric battery powered motor. During operation of the climbing device a rope is introduced in the rope pulley, and once the motor is engaged and starts to rotate, the rope pulley may advance the climber in a typically vertical direction along the rope.
Even though the above mentioned prior art shows a very useful solution for rope access to heights, there is always an endeavor to introduce further improvements for the personnel utilizing the equipment. Specifically, there is a desire to minimize any risks when working at heights, thereby improving the environment for the user of such equipment.